Timing device



T. R ARDEN TIMING DEVICE Nmn 6, 11951 Filed Feb. 26, 1948 INVENTORDThunw Rolfirdem Patented Nov. 6, 1951 UNITED TIMING DEVICE Thomas R.Arden,'Danbury,' Conn, assignor to Bard-Parker Company, Inc., Danbury,Conn., a

corporation of New York Application February 26, 1948, Serial No. 11,200

6 Claims.

This invention relates to timing devices, and has particular referenceto a timing device which is especially intended and designed toautomatically stop the operation of model airplane engines topredetermine and limit the time periods during which the airplanes arepowered in their flights. The present timer may, however,

readily be adapted to perform other timing purposes.

One reason for limiting the duration of powered flights of modelairplanes is to avoid flying of the same long distances from theirlaunching points and thereby becoming lost. More importantly, however,in model airplane contests, flights for records and the like, theairplanes usually are flown against time rather than against oneanother, and a basic factor in determining and comparing theirperformances is the time during which they are powered in flight. It isimportant, therefore, to provide a timing device by means of which thetime during which model airplanes are powered in their flights may bepredetermined very accurately.

Accordingly, one special and important object of the present inventionis to provide a timing device which is thoroughly reliable in operationto predetermine accurately the length of time during which a modelairplane is powered in its flight. a

' Another special and important object of the invention is to provide atiming device which may readily and easily be adjusted to vary theamount of time during which it operates toperform its function, therebytov variably predetermine the time periods of events which itcontrols,;as,- for example, the time period during which amodel airplaneis powered in its flight.-

Another special and important object of the invention is to provide atiming device which completes its operation with a quick action, wherebyit is rendered very accurate in the performance of its timing purpose. I

In model airplanes, conservation of space and reduction in weight areimportant considerations. Accordingly, another object of the inventionis to provide a timing device which may be quite small in size and ofvery light weight. a

The present timing deviceis designed to stop an engine by cutting offits fuel supply, and in this connection another object of the inventionis to provide'a timing device which is designed to accomplish thispurpose reliably and positively.

The'p'resent' timing device is, moreover, of the cylinder and piston,hydraulictype, andin this connection another object of the. invention isto provide a timing device of this type which utilizes as its liquid thefuel which it controls.

With'the foregoing and other objects in view, which will become morefully apparent as the nature of the invention is better understood, thesame'consists of a timing device embodying the novel features ofconstruction, combination, and arrangements of parts, as are illustratedby way of example in the accompanying drawings and as will behereinafter more fully described and claimed. s

In the accompanying drawings, wherein like characters of referencedenote corresponding parts in the different views:

Figure 1 is a central, longitudinal section through a timing deviceconstructed in accord ance with the invention. 1

Figure 2 is an end view of the device; and

Figure 3 is a cross section on the line 33 of Figure 1.

Referring to the drawings in detail, it will be observed that thepresent timing device comprises a cylinder II] which is closed at oneend by a head H and which has slidable therein a piston 12 which isurged constantly toward the head II by a spring [3. I i In the head IIand extending transversely thereof is a fuel passageway M which, at oneend, is provided with a nipple or other suitable fitting 15 forconnection with a fuel supply line and which, at its other end, is incommunication with a valve chamber IS in said head. I

A bore I! in the head I l provides communication between the fuelpassageway I4 and the cylinder space a between said head I] and thepiston l2 under the control of a check valve [8 which opens toward saidcylinder space aand closes toward said fuel passageway. Thus, uponmovement of the piston 12 in the cylinder [[0 away from the head ll,fuel will be drawn into the cylinder space a through the bore H, butwill not escape from said cylinder space through said bore upon movementof said piston toward said head ll.

The valve l8 may appropriately be a ball, and a spring I9 preferably isprovided to maintain it closed except when the piston I2 is moved awayfrom the head II.

The piston I2 is intended to be moved manually away from thehead II andto that end is provided with a suitable handle 20 which mayappropriately be in the form of a rod disposed in axial alignment withsaid piston and extending therefromthrough a guide opening in a 010- sreil; o th 5. 9i th s li l"; WmQW' P- the end thereof which is closed bythe head II. In this connection, the spring I3 may appropriately be ahelical expansion spring as shown and may be interposed between thepiston I2 and the closure 2| so as to perform its function of urgingsaid piston constantly toward the head I I.

In the head I I is a duct 22 which connects the cylinder space a withthe fuel passageway I4 and which has associated therewith a suitablevalve 23 for varying its effective cross sectional area.

As shown, said valve 23 may appropriately be of the needle type and maybe threaded in the head II so that by rotation thereof its inner,pointed end may be moved into and from the duct '22 to vary theeffective cross sectional area of the latter. A suitable handle 24 onsaid valve 23 exteriorly of the head I I affordsa convenient means forfinger engagement to effect desired adjustments of said valve.

The valve chamber I6 extends longitudinally of the head II and at itsinner end is connected with the cylinder space a by a port 25, while atits outer end it is provided with a suitable fitting 26 for connectionwith a part of the fuel supply line leadin to an engine.

In the valve chamber I6 is a valve member 21 of the spool type which, atits inner end, .is providedwith a'valve formation 28 for cooperationwith a seat surrounding the portto control flow of fuel through saidport, and which, at its :1

outer end, is provided with a second valve formation 29 for cooperationwith a seat constituted by the inner end of the fitting 25, or'byanyother suitable means, to control flow of fuel from the chamber I6 tosaid fitting 26.

The distance between the valve formations 28 and 29 is slightly lessthan the distance between the seats with which they cooperate.Consequently, when either of said valve formations is closed, the otheris open. In this connection, a

suitable spring 30 tends constantly to move the valve member 21 inwardlyand hence maintains the valve formation 29 normally closed and the valveformation 29 normally open.

Extending from the inner end of the valve member21 through the port 25into the cylinder space a is a stem 3I which is engageable by the pistonI2 just prior to said piston reaching its limit of movement toward thehead -I-'I, so that by the final small amount of movement of said pistontoward said head I I, the valve member-21 is moved positively outwardand thereby the valve formation 28 is opened and the valve formation 29is closed. In this connection, the

effective cross sectional area of the port 25 and the strength of thespring 30 are such, in relation to the strength of the spring I3, thatthe valve member 26 is not moved outwardly by the pressure generated inthe cylindrical chamber a by said spring I3, but only by positive actionof the piston I 2 against the-stem 3 I.

Suitable means, such as a laterally flexible spring arm 32 suitablyfastened to the closure 2I and engageable in an annular channel 33 inthe handle rod '20, is provided to releasably hold the piston I2 in astarting position spaced any suitable distance from the head II.

Assuming that the timer is interposed in an engine fuel supply line;that the cylinder space a. is devoid of fuel, and that the piston I2 isat .its limit of movement "toward the head II, it is apparent that byexerting a pulling force on the handle .rod 20 the piston will be movedaway from thehead II 'and thereby fuel will be drawn freely into thecylinder space a. through the bore 4 I! from the fuel line constitutedin part by the passageway means afforded by the passageway I4, the valvechamber I6 and the fitting 25. It will further be apparent that bypulling on the handle rod 28 until the channel 33 becomes alined withthe spring arm 32 and the latter engages in said channel, a definitestarting position of the piston I2 will 'be established and a definiteamount of fuel will be contained in the cylinder space a.

Once the cylinder space a has been charged withfuel in the manner statedand the piston I2 is in its starting position, the spring arm 32willactyby engagement with the channel 33, to maintain that conditionindefinitely or, in other words, until the spring arm 32 is flexed fromsaid channel 33 by finger pressure exerted against said arm. Thus theengine may be operated as long as desired prior to initiation of apredetermined time period of operation thereof by manual release of thespring-arm 32, since the normally open valve formation-29 will permitfree flow of fuel from the source of supply to the engine.

Upon release of the spring arm 32, the spring I3 will act to urge thepiston I2 toward the head I I and to force the fuel contained in thecylinder space a from said cylinder space. Since the checl: valve I8will prevent flow from the cylinder space a through the bore I1, and thenormally closed valve formation 28 of the valve member 21 will preventflow of fuel from said cylinder space a into the valve chamber IS, theduct 22 obviously constitutes the only avenue for escape of fuel fromsaid cylinder space a. The rate at which fuel may escape from thecylinder space a through the duct 22 determines the rate of movement ofthe piston I2 toward the head II by the spring I3 and hence determinesthe amount of time required for said piston to move from-its startingposition to its position in which it contacts the stem 3| and opens thevalve formation 28. The valve .23 constitutes .an adjustable means forvarying the effective cross sectional area of the duct .22 and hence therate of escape offuel therethrough from the cylinder space a.Accordingly, by adjusting said valve 23, the time required for thepiston I2 to move from its starting position to its position in which itengages the stem 3| and opens the valve formation 28 may be variablypredetermined.

When the piston I2 engages the stem 3| and opens the valve formation 28,fuel may escape freely from the cylinder space a through the port 25 andhence the final portion of the movement of the piston I2 toward the headI I is quite quick. When the valve formation 28 is opened the valveformation 29 is simultaneously closed, thereby cutting off the fuelsupply to the engine and causing the same to stop. Obviously, the valveformation 29 will be maintained closed until the piston I2 again ismanually moved outwardly relative to the head I I, whereupon :the spring38 will act to shift the valve member 21 to close the valve formation 28and open the valve formation 29-.

If desired, but not necessarily, a check valve 34 may be included in theoutlet portion of the fuel line between the valve chamber I6 and theengine to prevent fuel from being withdrawn from this portion of thefuel line when the piston I2 is. moved outwardly relative to the head tocharge the cylinderspace a with fuel. Appropriately, said check valve 34may be incorporated in the fitting '26, as shown.

7,: v Obviously, the present timingtdevice mayyadvantageously be of verysmall sizeand light weight and possesses the further advantage that itutilizes the fuel which it, controls as the liquid medium for itshydraulic operation. It is, moreover, smooth and positive in operationand in itself constitutes a fuel reservoir so that the fuel tank may, ifdesired, be correspondingly reduced in size. It furthermore'acts, bysubjecting the fuel in the fuel line to pressure, toinsure supply offuel to the engine.

From the foregoing description considered in connection with theaccompanying drawings, it is believed that the construction andoperation of the'present timing device willbe clearly'understood and itsadvantages appreciated. It is desiredto point,out,, however, that whileonly a single, specific structural embodiment of the invention has beenillustrated and described, the same is readily capable of specificallydifferent structural embodiments within its spirit and scope as definedin the appended claims.

I claim:

1. A timing device comprising a cylinder, a head closing one end of saidcylinder and having therein passageway means constituting part of aliquid supply line, a piston in said cylinder movable toward and awayfrom said head, means for the free flow of liquid from said passagewaymeans into said cylinder between said head and said piston when saidpiston is moved away from said head, spring means to move said pistontoward said head, releasable means to hold said piston in a definitestarting position spaced from said head, means providing two outlets forliquid from said cylinder to said passageway means, a spring biasedvalve maintaining one of said outlets closed against pressure generatedin said cylinder by movement of said piston toward said head by saidspring means, a valve adjustable to vary the eifective cross sectionalarea of the other of said outlets to regulate the rate of flow of liquidfrom said cylinder to said passageway means and thereby vary the timerequired for movement of said piston from its starting position apredetermined distance toward said head, means whereby said piston actspositively to open said spring-biased valve following a predeterminedamount of movement of said piston toward said head thus to permit freeflow of liquid from said cylinder to said passageway means andconsequent quick movement of said piston during the final part of itsmovement toward said head, and other valve means operable by said pistonduring the final quick portion of its movement toward said head to closesaid passageway means against flow of liquid therethrough.

2. A timing device comprising a cylinder, a head closing one end of saidcylinder and having therein passageway means constituting part of aliquid supply line, a piston in said cylinder movable toward and awayfrom said head, means for the free fiow of liquid from said passageway Imeans into said cylinder between said head and said piston when saidpiston is moved away from said head, spring means to move said pistontoward said head, releasable means to hold said piston in a definitestarting position spaced from said head, means providing two outlets forliquid from said cylinder to said passageway means, a spring biasedvalve maintaining one of said outlets closed against pressure generatedin said cylinder by movement of said piston toward said head by saidspring means, a valve adjustable to vary the effective cross sectionalarea of the head,;and a normally open valve fixed with re-.

spect tosaid spring-biased valve and movable with-the latter duringopening thereof to close said passageway means against flow of liquidtherethrough.

3. A timing device comprising a cylinder, a head closing one end of saidcylinder and having therein a liquid passageway and a valve chamber withwhich said passageway is connected, a piston in said cylinder movabletoward and away from said head, spring means to move said piston towardsaid head, a check valve-controlled bore permitting free flow of liquidfrom said passageway to the cylinder space between said head and saidpiston and denying flow of liquid from said space to said passageway,releasable means to hold said piston in a definite starting positionspaced from said head, a duct for flow of liquid from said cylinderspace to said passageway, an adjustable valve to vary the rate of flowof liquid from said cylinder space through said duct to said passageway,said valve chamber being in communication with said cylinder space, saidhead having a liquid outlet communicating with said valve chamber andthrough the latter with said liquid passageway, a valve member in saidvalve chamber having two valve formations one controlling flow of liquidbetween said cylinder space and said valve chamber and the othercontrolling flow of liquid through said outlet, spring means effectiveto hold said first mentioned valve formation normally closed against thepressure generated in said cylinder space by movement of said pistontoward said head by said first mentioned spring means and to hold saidsecond mentioned valve formation normally open, and means whereby saidpiston acts positively during the final portion of its movement towardsaid head to shift said valve member to open said first mentioned valveformation and to close said second mentioned valve formation.

4. A timing device as set forth in claim 1, in which the passagewaymeans includes an outlet portion to one side of the last mentioned valvemeans, having therein a check valve to prevent flow of liquidtherethrough toward said second mentioned valve means.

5. A timing device designed to perform its timing function by cuttingoff flow of fluid through a conduit after the elapse of a predeterminedperiod of time, said device including a fiuid conduit and a chamber,means providing for free flow of fluid from said conduit to said chamberand for throttled flow of fluid from said chamber to said conduit, amember movable outwardly in said chamber to increase its effective sizeand thus draw fluid into the same from said conduit, means operable inresponse to a predetemined amount of movement of said member into saidchamber to provide for free flow of fluid from said chamber to saidconduit and thus provide for quick movement thereafter of said memberinto said chamber, and means operable in response to said quick throughsaid: conduit.

' 6 A' timingdevioe to out off the fuel supply to an 'en gine and thus"automaticallv stop the engine after the elapse of apr'edeternlinedperiod of time, said'deviceincluding a chamber and means for connectingthe same with an engine fuel supply conduit for free flow of fuel to thesame from the conduit and for throttledfiow of fuel from the same to theconduit; a member movable outwardly in said chamber to increaseits'efiective size and thus drawffuel into the same from said conduit,spring means for moving said member into said chamber 'to expel fueltherefrom into said conduit; a valve for controlling flow of fuelthrough the conduit, said valve being normally open, means operable inresponse movement of said member tocut off fiovv of to a predeterminedamount of movement of said member into said chamber to provide for freeflow of fuel from" said chamber 'to' said conduit and thus provideforquick movement thereafter 01' said member into said chamber, andmeans'op erable in response 'to said quick movement of said member toclose said valve and'thus cut off flow of fuel through said conduit.

' THOMAS R. ARDEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Date

